铝合金阳极氧化膜封闭技术发展趋势

Development Trend of the Sealing Technology for Anodic Films on Aluminum Alloys

铝合金因其具有高的比强度、比刚度和良好的成型加工性能,被广泛用于航天、航空、交通运输、建筑等领域。大多数铝合金产品需要通过阳极氧化表面处理来提高其耐蚀性能。典型的铝合金阳极氧化膜由外部厚的多孔层和内部薄的阻挡层组成。这种多孔型阳极氧化膜本身耐蚀性能不足,需要对其进行封闭处理,封闭处理技术的好坏直接决定了阳极氧化铝合金产品的生产成本和使用性能。首先概述了水合封闭、金属盐封闭、溶胶凝胶封闭和有机封闭4类常见的铝合金阳极极氧化膜封闭技术;在此基础上,综述了金属盐封闭技术的发展趋势,特别是层状双金属氢氧化物封闭铝合金阳极氧化膜的国内外研究进展,以期为新型铝合金阳极氧化膜封闭技术研发提供指导。

Aluminum alloys are widely used in aerospace,aviation,transportation,construction and other fields because of their high specific strength,specific rigidity and good forming performance.Most aluminum alloy products require anodizing surface treatment to improve their corrosion resistance.A typical anodic film on the aluminum alloy is composed of a thick porous outer layer and a thin barrier inner layer.The porous anodic film itself has insufficient corrosion resistance and requires post-sealing treatment.The quality of the sealing treatment directly determines the cost and performance of anodized aluminum alloy products.This article first summarizes four common sealing technologies for anodic films on aluminum alloys,namely hydration sealing,metal salt sealing,sol-gel sealing,and organic sealing.Further,the development trend of metal salt sealing technology was reviewed,with focus on research progress on sealing of the anodic film with layered double hydroxides.This paper will provide a guidance for the development of new sealing technology for anodic films on aluminum alloys.